Remote control sectionalized antenna



Sept. 14, 1943.

, 1941 5 Sheets-Sheet 1 Filed Aug. 21

Fleylj F'IG.2

INVENTOR. 1-6;&&:

ATI'ORNEY Sept. 14, 1943.

a J. HEFELE' I REMOTE CONTROL SECTIONALIZED ANTENNA 5 Sheets-Sheet 2FIGS.

FIG.5.

INVEN'TGR.

ATTORNEY Sept. 14, 1943.

E. ,1. HEFELE REMOTE CONTROL SECTIQNALIZED ANTENNA 5 Sheets-Sheet 3Filed Aug. 21, 1941 Flea.

myuuums INCREKSE necnsnsn I @425 MANUAL 'ru'ums A'ITORNE Sept. 14, 1943.E, J. HEFELE REMOTE CONTROL SECTIONALIZED ANTENNA Filed Aug. 21, 1941 5Sheets-Sheet 4 QOE INVENTOR.

ATTORNEY Sept. 14, 1943.

E. J. HEFELE REMOTE CONTROL SECTIONALIZED ANTENNA Filed Aug. 21 1941 5Sheets-Sheet 5 INVENTOR.

ATTORNEY Patente d Sept. 14, 1943 Edward J. Hefele, New York, N.asslgnor to Jefferson-Travis Radio Manufacturing Corporation, New, York,N. Y.,a corporation of New 7 York Application Augustzl, 1941, Serial No.401,740

37 Claims.

My invention relates in general to the field of radid transmission andmore particularly to a novel and improved form of sectionalized an-.v

tenna having remotely adjustable impedance and transmissioncharacteristics.

In the transmission of radio frequency energy v by 'a vertical antenna,the vertical directivity thereof .and various other transmissioncharacteristics are directly dependent upon the length of the antennaand the effective height of the antennaf These constants of a verticalradiator are gen- 'erally fixed if' a straightv rod antenna is employed.

Heretofore,- various means have been'devised'. for varying thesecharacteristics to improve the transmission efllciency of a radiotransmitter.

4 For a conventional vertical antenna, the-current-distribution variesfrom a maximum at the lowest point thereof to zero at the uppermostpoint thereof in a substantially linear manner.

This current distribution characteristic is eiiec-' tive in determiningthe amount of radio frequency energy radiated from this antenna. In-

asmuch as the current through the upper portion of the antenna, capableof maximum radiation, is comparatively low, the over-all transmissionemciency is correspondingly small.

In one-form of improved antenna design, the

vertical radiator is divided at substantially the the sectionalizingcoils were of a fixed impedance. 7 As a result, the transmitting antennawould be operative as a sectlonalized improved radiator fora singlefrequency. -At any particular frequency, the impedance of asectionalized coil is predetermined so that the antenna is resonant atthat frequency.

In many circumstances, it is desirable to adfiust the impedance of thesectionalized-coil for resonance at each of a plurality of differentfrequencies as wellas to make adjustments for improving the radiatingcharacteristics for any one frequency.

My invention contemplates a sectionalized vertlcal antenna in which theloading impedance Y has adjustable characteristics so that optimumtransmission emciency may be obtained from any frequency utilized at thetransmitter. In'addition, my vertical sectionaliaed-antenna is adaptableto transmission circuits where any one of a plurality of fixedfrequencies may be utilized for the transmission of a signal.Accordingly,

. my sectionalized antenna utilizes an impedance midpoint by aninsulating member thus separat ing' the upper and lower metallicsections thereof.

An impedance usually in the form of a coil of wire is electricallyconnected between these two sections ,of the antenna and hence acontinuous vertical radiator is formed. This type of antenna, known as asectionalized or loaded antenna has the characteristic that, at aparticular frequency which is determined by the antenna capacitanceconstants and the' impatience of the aforementioned coil, a more uniformcurrent distribution occurs over the-antenna. This results in acomparatively high current flow in the upper section of the antenna as 1compared to the prior vertical antennas which were not loaded. Thisincrease in current in the higher section of the antennaaccordingly-improves the transmission efiiciency thereof.-

. cushion the e'fiect of any physical shock imposed In short, theinsertion of inductance to em trically connect the two sections 'of avertical radiator increases the effective height of the radiator withouta corresponding increase in the physicalheight of the antennastructure.-

Heretofore, sectionalized antenna 'weredesigned to' meet aparticularinstallatlon' and thus such as a variable condenser oraninductance coil in which the numberoi turns inserted between thesectionalized lengths of the antenna is variable by simple automatic andmanual means. Although particularly adaptable for mobile installations,it may beemployed wherever adjustments of the transmitter antenna aredesired. 1

The vertical antenna of my invention when mounted upon a verticalstandard may project for a number of feet, and, therefore, I provide aspecial mounting which will absorb shocks accidentally imposedthereupon-when passing under' low bridges and the like and iscollapsible when the vehicle is to be stored within a garage or thelike. a

, I may also provide a pilot whip for the antenna to swing the antennaout of position to avoid any contact thereof with obstructions .ofvarious kinds; and, either in combination therewith, or

in the alternative, I may provide a special bumper or shock absorber onthe antenna itself' to directly on the antenna.

The entire antenna system forms a compact, easily adjustable mechanismso that whatever the frequency utilized for the transmission of energy,the antenna maybe adjusted for a maximum effective height and powerradiation efliciency.

It is, therefore, an object of my inventiomto provide .a novel verticalantenna of aut cally and manually variable-impedance charac to providemeans for'swin'ging the antenna out of position to avoid physicalshocks, and, in combination therewith, or, in the alternative, toprovide shock absorbing means on the antenna itself.

Another object of my invention is to provide for a sectionalized antennahaving a loading coil,

. the effective turns of which are adjustable.

Still another object of my invention is to provide for a sectionalizedantenna having a sectionalizing coil which is adjustable by automaticmeans operative from a remote point to provide maximum radiationefficiency.

These and other objects of my invention. will 1n part be apparent, and,where not apparent,

rated from each other by the insulating block l3 (see especially Figure3).

The bulb-like housing I4 acts as a connecting member for securing theupper section II to the insulator l3 and in addition contains thenecessary sectionalizing impedance which may be in the form of anadjustable loading coil or a varior other insulating material.

pointed out in the following description and drawings in which:

Figure 1 isa front view of my novel sectionalized antenna and themounting thereof.

Figure 2 is a side view of the sectionalized antenna of Figure 1.

Figure 3 is a" cross-sectional view taken on line 3--3 of Figure 1. v

Figure 4 is a cross-sectional view, partly in plan, taken on line l| ofFigure 3 looking in the direction of the arrows. i

Figure 5 is a cross-sectional view partly in elevation taken on line 55of Figure 8 looking in the direction of the arrows.

Figure 6 is a cross-sectional view, partly in elevation, taken on line6-4 of Figure 8 looking in the=direction of the arrows and showing adifferent position of the members of Figure 5.

Figure 7 is a cross-sectional view, partly in elevation, taken on line I-I of Figure 8 looking in the direction of the arrows.

Figure 8 is a cross-sectional view, partly in elevation, taken on line88 of Figure 2 looking in the direction of the arrows.

Figure 9 is a cross-sectional view taken on line 99 of F1 re 8.

Figure 10 is a cross-sectional view taken on line Ill-l0 of Figure 8.

Figure 11 is a cross-sectional view taken on A shaft I1 is rotatablymounted in bearings 2|, 2| of the supporting brackets l8, l8, the saidsupporting brackets being in turn secured to' a base plate [9. The baseplate I9 is secured in any suitable manner as, for instance; by thebolts 1 20, 20 to the shock absorbing mountings I6.

The lower vertical radiator I2 is secured in the tubular supportingbracket 22 which, in turn, is

inset in a recess 23 in the rotatable shaft I! (see also Figure 8). Thetubular member 22 and hence the lower endof the lower vertical radiatorI2 is clamped in place by means of the clamping plates 24, 24 which arerecessed and hollowed out to surround the tubular member 23 and whichare alsohollowed out, as seen in Figures 8 and 10,

'in order to provide a housing for the motor and The clamping plates 24are secured to each other on either side of the rotatable shaft I! bybolts 26, 26, which bolts pass through a portion of the tubular antennasupporting member 22 and also the shaft l1 and surround the motorhousing 25 and thus serve securely to hold the motor housing 25 in placeand to securely position the lower end of the radiator withrespect tothe shaft.

Accordingly, the shaft l1 and the entire radiator l0 may rotate withrespect to the frame l5 of the vehicle on which the apparatus ismountrangement of the entire structure will permit the entire'antennastructure above the shaft H to be revolved to a horizontal position.

Such horizontal position may be obtained by manually grasping androtating the antenna or will occur if the antenna should strike a lowobject. The pivotai arrangement for the vertical radiator is, however,suoh'that the entire an-'-.

tenna structure I0 is self-erecting and there is a normal bias tendingnormally to maintain the entire antenna structure III in a verticalposition.

whip for moving the same out of position to avoid an obstruction.

Figures 13 and 14 are views in perspective showing'modiflcations in theconstruction of the apparatus of Figure 12.

Figures 15 and 16 are front and side views re-- radiator I I and a lowervertical radiator l2 sepa- The members for normally maintaining theentire radiator III in vertical position comprise a pair of crank arms30 fixedly mounted on the rotating shaft l1 and so arranged thatrotation of endof each tensionspring being connected at 34, 35 tobrack'ets on the base plate l9;

It will thus be clear that any force which may tend to rotate thevertical antenna structure III to a horizontal position, for instance ina counterclockwise direction, will result first in a slight compressionof spring 32 and an extension of spring 33, and continued rotation willresult,

as seen particularly by the dotted lines of Figasaacoo ure 5, in an.extension of both of the tension springs 33 and 32.

This will normally tend to cause the crank arm 30 to rotate once more tothe-position shown by the solid lines of Figures and 6 to cause thevertical antenna structure ID to erect itself once more in verticalposition.

The tension springs 33' and 32 hence serve accurately to align thevertical antenna'structure and by working against each other to maintainthe vertical antenna structure in a position normal-to the plate l9 andhence to the surface l5 of the frame structure to which the entireapparatus is connected.

Since the mounting for the antenna structure shown by the dotted lines,the dashpot arm 44' is still connected to the crank arm 30 of'thevertical .antenna structure since an extension of the member 5i on themember 50 occurs.

The springs 33 and 32-would normally tend to snap back the verticalantenna structure violently and thus cause an excessive vibrationthereof, but

the dashpot 40 through its crank arm 44 resists thissudden action andslows it up. so that the antenna structure is brought back slowly andvibration is impeded.

and so that they will not normally permit rotation of the antennastructure under the influence of vibratory stresses which should notcause the antenna structure to assume a position other than vertical.

Various types of damping members may be used. Thus, for instance,dashpots 80 may be mounted on the plate is of the antenna structure bymeans of brackets 42 and in any other suitable manner. I

The dashpot to, as is seen in Figures 5 to 8 inclusive, has a shaft 43extending therefrom. The dashpot is so arranged that it resists rotationof the shaft 613 and hence clamps any force which tends to causerotation of the shaft t3.

An extensible crank arm Mis secured to the shaft 53 and rotatabletherewith. The crank arm at hasa pin 65 at the free end thereof,

the said pin registering in the slot 36 of the crank arm 30. i v

Any rotation of crank arm will through the pin 55 and slot 46arrangement cause the crank arm ie of shaft 13 to rotate and hence anymovement of the crank arm 3% .will be resisted by the damping effect ofthe dashpot to,

As will be seen, however,' from Figures 5 and 6, the rotationof crankvarm 30 around the shaft i1 causes the various portions of the crank arm30 to change their distance with respect to the dashpot til and thecrank arm it thereof. Acorder to ensure that there will alcordingly, iwaysbe an operative engagement between the dashpot it-and the crank arm30, the slot t6, rather than a pivotal arrangement, is necessary forsecuring the pin 45 of the dashpot to the crank arm 30.

Also the crankarm M of the dashpot must necessarily be extensible inorder that an ap- In this manner, the vertical-antenna structure mayreadily be swung out of position either manually or by any obstructingforce which may come in contact therewith and may readily swing backinto position upon relaxation .of such force, and any undue orunnecessary vibration is obviated.

While I have thus far shown and described the mounting of my antennastructure as one which will permit the antenna structure to be swung outof the way by a manual force applied to the antenna structure or anyother motive force applied.

thereto or in the alternative by its striking an obstruction, additionalmeans'may nevertheless be provided to work the antenna structure so thatit will not be struck by any obstruction and so that it will be swungout of the way immediately be-.

fore such an obstruction is reached. 'For this purpose, as seen inFigures 12, 13 and 14, I may provide what I have termed a pilot whiparrangement 60 which will first com in contact with the obstruction andwill be operated thereby to swing the antenna. structure out of the way.

5 As seen, forinstance, in antenna structure it is mounted on the top ofFigure 12, the vertical moving vehicle it by means of the base plate asand the other structures hereinbefore described. A pilot whip (it ispivotally mounted on brackets 6 i, ti and is normally supported byaspring bias or in any other suitable manner in the vertical positionshown in Figure 12. The pilot whip at has sufilcient height to contactany obstruction which may normally strike the antenna structure or themore essential parts thereof, as, for instance,,the bulb-shaped member ii;

When the pilot whip ht strikes an it will, in the modification shown inFigure 12, be deflected to close a switch to a motor 53 which willimmediately wind up the cable 6t attached to "the antenna structure,ltand deflect the same to the position shown by the dotted lines ofFigeither by the motopitseli or by the obstructionure 12. The antennamay then be held down under which it passes'until the obstruction hasbeen passed, and the erecting structure, consistpropriate engagement mayexist between the dashpot and the crank arm 30. For this purpose thecrank arm M which is attached to the shaft 33 of the dashpot Bil is adouble member consisting of a crank arm 5t directly secured to the shaft63 and a slide member 5! whichis slidable on the arm 50 (seeparticularly Figures 6 and 7). The pin t? is carried on the free end-ofthe slide member 5!.

While the member 5| is slidable on the member 50, it neverthelesshas'thel same radial relation to the shaft 43 as does the member 50. Nowas seen .in Figure6, when the vertical antenna structure is rotated fromthe position tical position. Or a snap locking member 65 may be mountedon the posts $5 to secure the antenna in the lower dotted line positionwhen the antenna has been depressed and to hold the antenna in thedepressed position until it is manually or otherwise positively releasedso that the springs 32 and 33 may operate to erect the same.

Various types off-apparatus may, of course, be utilized following thesame principles. Thus, for

. instance, the pilot whip'tii' of Figure 13 may be arranged so thatwhen it is moved to the dotted line position of Figure 13, it willactuate the switch member .llii to initiate the operation of the vacuum,motor H which may be operated from the intake manifold and thus causeits shaft 12' and hence the, crank arm 13 to rotate. The crank am 113may be connected by cable ,3 by the solid lines to the position shownobstruction,

I4 to a bracket I5 on the antenna structure.|8 and thus serve to rotatethe antenna structure I8 in a counter-clockwise position with respect toFigure 13 and hence lower the same.

The rotation once more of the pilot whip 88' to the position shown bythe dotted lines of Fi ure 13 when the obstruction is removed mayopcrate the switch member I8 to permit the antenna I8 to be raisedeither by the vacuum motor 'II or by its own springs 32 and 33.v

In another and preferredmodification as shown in Figure 14, the antennastructure I8 may be connected by a cable or link 88 to a crank arm 8|fixedly mounted on a shaft 82 which in turn is 'rotatably mounted in itsbrackets 83 and 84.

Crank arm 85 is also fixedly mounted on the shaft 82 and may extend toone side of the mounting plate I9 of the antenna structure I8.

A link 85 may be pivotally connected to the crank arm 85 at one end andthe other end pivotally connected to the crank arm 81 which, in turn, isfixedly mounted on the rotating shaft 88 which rotates in its brackets89 and 98. The pilot 'whip 8| may be fixedly mounted on the shaft 88'tate the shaft 88 and hence the crank arm 81.

Rotation 01' crank arm 81 will through the link 88 cause rotation ofcrank arm 85, which will, in

' turn, rotate the shaft 82. Rotation of shaft 82 will rotate crank arm8| and hence exert counterclockwisepull on the cable or link 88 and-thuscause a rotation of the antenna structure I8 in a a counterclockwisedirection. so that it will b depressed inhorizontal position.

The advantage of the construction shown in Figure 14 is that there is adirect positive mechanical linkage between the, pilot whip 8| andtheantenna structure I8 so that as soon as any rotative motion isinitiated with respect to the pilot whip 9|, corresponding rotativemotion will b transmitted to the antenna structure I8.

No spring or other means need necessarily be provided to cause the pilotwhip III to move once more to erected position when the obstruction ispassed, si'ncc'the erecting spring 82 and 88 of the antenna structurewill notonly serve to erect the antenna but through the mechanicallinkages above set forth will also cause the pilot whip 8| to be erectedonce more.

In any of the structures above described, however, the essentialrequirment is that the pilot whip be so linked to the antenna structureas to cause a rotation of the antenna structure toward at its upper endat I84 and therefore when this member is positioned on the insulatingblock I8 and appropriately secured thereto, the interior of the metallicmember is sealed from the atmosphere.

The cylindrical metallic member I83 forms the interior lamination orsurface of the bulb-like housing I4. The metallic cylinder I88 has aplurality of vertical fins I81 projecting therefrom (see particularlyFigures 1, 2 and 3) in order to rigidify and strengthen the structure.These metallic vertical fins I81 also provide an acurate positioningmeans for a rubber bumper I88 which may consist of a longitudinal stripof material arranged in such manner that one section thereof ispositioned between the vertical fins I81 on one side of the housing Itand the other section is positioned between the vertical fins II" on theopposite side of the housing, as seen in Figures 2 and 3; a portion ofthe rubber bumper I88 going over the top of the housing I4 and beingsuitably perforated at I I8 to permit the upper vertical antenna sectionII to project therethrough.

The bumper of suitable shock absorbing insulating material may then besecurely positioned in place by extending the ends III, III thereof,down onto the outside of the tube I2 beneath the housing I4 and bysecuring a collar II4 around the neck III.I II thus formed. The saidcollar H4 may then be held in place in any suitable manner as, forinstance, by the screw II 5 passing through flanges of the collar andheld by the nut H8.

By this means, therefore, the rubber bumper may readily be replacedshould it become worn or damaged by reason of contact with obstructions.It will be necessarymerely to remove the upper antenna red I I in themanner hereinafter set forth and loosen the collar IH', slip anotherbumper I88 in place in the manner shown in Figures 1 to 3, replace andtighten the collar I I4 and replace the upper rod I I..

The material for bumper I88 and insulating block I8 should be of aninsulating material such as a polystyrene. compound good for radiofrequency. If a suitable radio frequency insulating material cannot beused for bumper I 88 then the a horizontal position before theobstruction is reached.

The lower section I2 of the vertical radiator,

as has been pointed out above, i a hollow tube.

--The cylindrical metallic member I88 is closed bumper I88 should notextend down around tube I 2. Or, in the alternative, bumper I88 maybypass the insulating block I3 and be spaced therefrom by a substantialair gap, and sufilcient material should be provided in the bumperbetween antenna sections II and I2 to provide a *sufliciently'longcreepage path.

The upper portion of the inner metallic cylinder I88 may have anintegral boss I28 connected thereto, the said boss being tapped at I2Ito permit the insertion of the threaded end I22 of the upper verticalantenna section II, the said upper antenna section being then rigidlysecured in closure I88 and the vertical radiator II is eflectivelyinsulated fromthe lower tubular radiator I2 by the insulating member orblock I8.

An inductor I88 comprising a plurality of helically wound turns mountedupon a tube I8I of insulating material is vertically aligned andsupported within ,the housing I4 and hence in the interior ofthemetallic cylinder I88. I

The insulating tube IN is rotatably mounted upon a vertical integralrod-like extension I33 of the insulating block I8v and may rotate withrespect thereto. .In, order to rigidify the entire a,s29,aoo

' desired. any suitable friction reducing or spacing means may belocated therebetween. The lower -'end of the insulating tubeis connectedby means of a friction reducing ball bearinglstructure I40 to theinsulating block I3, thus facilitating the .rotation ofthe insulatingtube' I3I and the coil I30 with respect to the block'and with respect tothe remainder of the housing. I The insulating tube I 3| and hence thecoil I30 may be caused to rotate in any suitable manner.

A preferred means shown in the drawings comprises a vertical shaft I42which is mounted within the. lower tubular radiator I2. The lower end ofthe shaft I42 is connected to and driven by a motor within the housing25 at the lower end of th antenna structure.

The upper end of the shaft is suitably rotatably positioned by a ballbearing structure I44 in the lower'end of the insulating block I3. Adriving gear I45 positioned at the upper end of the shaft I42 isconnected with and drives a pinion I46 which, in turnfis positioned onthe rotatable shaft I41, the said shaft I41 being rotatable within avertical opening in the insulating block I3.

The-upper end of the shaft I41 on the upper side of the insulating-blockI3 carries a gear I48 which meshes with the gear I 49 (see'particularlyFigure 4) on the lower end ofthe tube I3I and thus transmits rotativeforce from the shaft I42 and the small shaft I41 to the tube HI andhence to the coil- I30.

It will thus be obvious that operation of the motor contained within thelower housing 25 in either direction will result in rotation of theshaft I42 and through the gears I45 and I45 and the shaft I41 andthrough the gears I48 and I49 will result in corresponding rotation ineither direction of the insulating tube I3I which carries t e coil I30.

The individual fturns ofwire'on the coil I30 .may either be spaced fromeach other and hence .wise formedthat the wiresare bare and hence maymake suitable electrical contact with the conductive follower I6 I edonthe verticalmetallic shaft I62, the said vertical metallic shaft beingsecured by the brackets, I53, I64 to the interior of the metallic-.cylinder I03. The lower end'of the coil I30 is n electrically connectedby the-wire I10 to the con tact brush "I which is'secured tothe tubularmember I3I and rotates therewith. The contact III is always in-contactwith the metallic ring I12 on the upper surface of the insulating blockI3. The said ring'I12 i's'electrically connected by the wire I13 passingthrough a, vertical perforation in theblock I3 to the upper end I00 of.the lower vertical antenna tube section I2;

The portions of the coil I30 remote from the lower end thereof may beelectrically connected to the r upper vertical antenna section IIthrough the conductive follower. IiI, the shaft I 62, the metalliccylinder I03 and the integral boss I which or slide I62. 20 coil I30 actas a screw, the rotation of which The conductive follower IBI isslidably mountconnects the upper vertical antenna section II to thecylinder I03.

Hence, in the construction shown in Figure 3,.

the lower vertical antenna section I2 and the upper vertical antennasection II have an inductance or loading coil I30 therebetween, thelower end of the coil being connected to the lower vertical antennasection and selected portions of the coil I30 remote from the lower endthereof In .being connected through the conductive follower IGI to theupper vertical antenna section.

As previously mentioned, the impedance or loading characteristics of thecoil may be varied by the operation of the motor contained within 15 thehousing and consequent rotation of the coil I30. The end of theconductive follower I6I is so arranged that it engages with the turns ofthe .coil I and is driven thereby upon its shaft For this purpose theturns of the drives the conductive follower.

' As the conductive follower changes the position at which itcontactsthe coil, the loading or impedance .characteristics of the coil areconsequently-varied, and the characteristics of the an tenna structureI0 are accordingly changed.

The upper end of the coil I30 is electrically free and mechanicallyfixedto the upper end of the tube I3I. It is obvious, therefore, that thenum- -ber of turns interconnecting the lower vertical radiator I2 withthe upper vertical radiator II will thus be dependent upon the positionof the follower I6I and hence will be determined by the rotation of theinsulating tube.

Since, as previously mentioned, in a sectionalized antenna, the currentdistribution is determined by. the individual inductive and capacitative reactances of the sections for a particular frequency, it will beclear that the sectionalized antenna'illustrated may be adjusted byrotation of the shaft I42 to emciently transmit any one of apredetermined range of frequencies. The exact position of the conductivefollower IIiI for any frequency may, of course, be determined by actualcalculation or experiment.

5o antenna through the sectionalizing coil contained in the enclosure I4and through the vertical rod. section I I. The utilization of thesection alizing coil and the upper and lower radiators II and I2,respectively, thus permits the current in the upper sections oftheantenna to beat a maximum value.

While in Figure 3 I have shown an arrangement whereby there is, nodirect connection between the top of the coil I3II and the uppervertical radiator II but ratherwherein the conductive follower to aparticular portion of the coil isthe ,sole connectionbetween the'coiland the upper radiator-the upper end of the coil may nevertheless bedirectly connected to the upper verti- -'cal' radiator II. In thislatter case, the conductive follower IBI may nevertheless be used andthe'movement thereof along the coil I30 will wherever it mayotherwise'be desirable, one end of the coil may be directly connected tothe upper vertical radiator 'II and the conductive follower Imay beelectrically connected to the lower radiator I2 to produce substantiallythe same results.

Since for the novel antenna disclosed, the entire vertical structure ispivoted about the shaft 11, it is necessary that the power. transmittedfor rotating the vertical shaft I42 be correspondingly pivotable. Asillustrated, therefore, in Figures 1 to 3, the enclosure 25 contains adriving mechanism including an electric motor and controlling mechanismfor determining the rotation of the coil I30 for any particularfrequency. This electric motor rotates the shaft I42 and is controlledby a contact mechanism whichis automatically operative from the controlbox of Figbeing at the lower end of the coil) to a maximum I inductance(which would correspond to a position of the follower at the upper endof the coil). Themaximum inductance of the coil may, of

course, be predetermined for a particular instal--.

lation.

In Figure 17 I have schematically illustrated a control system foradjusting the impedance of the coil by insertion of more or less coilturns to. vary the tuning of the antenna.

' I provide a motor which I have schematically illustrated at 2 having afield winding 212, the midpoint of which is tapped at M3 to theconductor 2. The armature of this winding is connected in shunt acrossthe current supply and in series with the radio frequency choke coils H6and 224 in the usual manner and, accordingly, is not specificallyillustrated here.

The conductor 2 may be carried through the tube or cable -2l5 (of Figure3) and thence through the radio frequency choke coil M6 to the positiveside of the current supply 2l9. An indicator lamp 2" and an on-off key2! are also connected in circuit with the-current supply M9. Theillumination of the lamp 2" indicates that the key M8 is closed inoperative position.

The "L terminal of the field winding 2l2 of the motor 2 extends over theconductor 22! ductor 225 to the 3" contact 221 of the manual switch 223and thence through the radio frequency choke coil 224 and the lamp 225to the negative side of the current supply 2l9. When switch 223 is movedto contact 221, a circuit is completed for driving the motor in adirection opposite to that when the circuit is completed through thecontact 222. v

.A plurality of individually adjustable wiping. contactors 2" to 240 aremounted in such manner that they are in sliding engagement with the disk242. The disk 242 and the wiping contactors 23| to 240 in contacttherewith are here illustrated schematically but it will be understoodthat, in general, the disk is arranged to make contact with all but oneof the sliding contactors 23l to 240 at any one time.

To this'end, in one form of my invention I provide this disk in the formof 'two sectors 243 and 244' separated from each other and insulatinglyspaced from each other by insulating material 242a. The disk is mountedon shaft 245 which is driven by the motor 2| 1 and as it rotates withrespect to the contacts to cause them to wipe thereover, one of thecontacts 23| to 240 will move out of wiping contact with the face of onesector of the disk and into the slotted or insulating portion 242a, asillustrated by the position of the contactor 231 in the drawings.

Each of the sectors 243 and 244 which make up the disk 242 with itsslotted or insulating portion 242a are thereby insulated from each'other and the sector 243 is connected by sliding contact 290 over wire246 to the R terminal of the field winding of the motor, the othersector 244 being connected by sliding contact 28l over wire 24! to the Lterminal of the field winding of the motor.

Each of the contactors 23| to 240 is connected individually byappropriate wires to the contacts 25! to 260 of the distributor 26l.Distributor 28l is provided with the rotating brush 262 which may bemoved to engage any one of the contacts 25| to 260. The brush 252, inturn, is connected over the radio frequency choke cbil 263 through theconductor 264 to the automatic terminal of switch 265 .and thence to thenegative side of the current supply 2l9. A lamp 255 is also pro-v videdfor indicating the arrangement of the switch in the automatic position.

As may be seen in Figures 15 and 16, the various members hereinbeforedescribed may be controlled by various knobs located on the outside ofthe control box and the various indicating lamps may likewise bepositioned to be visible from the control box.

the control box and the signalling lamps 2H,

225 and 256 which indicate the conditions of the various circuits arelikewise visible from the outside of the control box. Each of thecontacts 25| to 260 of the distributor 28L corresponds respectively tothe numerals 1 to 10 on the'outside of the control box surrounding thedistributor brush control knob. s

The operation of the circuits should nowbe obvious. The operator, havingfirst predetermined the particular frequency to which he desires to tunehis antenna, and havingtherefore determined the adiustmentnecessaryof'the impedance of the coil for effecting the necessary resonance, willset the distributor brush 202 to engage the particular contact member ofthe contacts'lil to 2" for effecting such adjustment.

At the same time, the switch 235 will be moved to engage its left handcontact or the contact which closes the circuit for the automaticadjustment mechanism, and the-on-ofl switch 2I6 will be operatedto itsclosed position. Operation of switch 2I8 will illuminate lamp 2 I1,indicating that voltage is being supplied for operation of theapparatus. 1 Operation of switch 265 also closes the circuit for lamp266 which by its illumination indicates that the automatic equipment iin operating condition.

Current will then flow from the negative side -of the current supplysource 2I9 over the auto- 246 through the right-hand portion of thefield winding 2I2 of the motor 2 over the mid-tap ofthe field windingand thence through conductor 2H and through the radio frequency chokecoil 2I6, on-ofl' switch 2I8 to the positive side of the current supply.

Current over this circuit will drive the motor 2| I, which, in turn,through the mechanical drive described above, will rotate the shaft I42carrying the impedance coil, while at the same time driving the. disk242 on its shaft 245. As the impedance coil rotates, the conductive cotactor ISI for the coil is moved in a vertical pat altering the amountof impedance in the antenna circuit.

Simultaneously with the rotation of the vertical shaft I42 which rotatesthe inductance, the-motor 2 also rotates the disk 242 which has beenarranged so that when a predetermined amount of impedance has beeninserted in the antenna circuit, the disk 242 has moved until theslotted insulating portion thereof 242a is opposite the contactor 234,which thereupon breaks the motor circuit traced above.

As a result, the motor is automatically brought In order to set'theantenna for some specific frequency within the frequency range of anyone of the contactors 23I to 240, each of these contactors is madeadjustable for movement along the disc 242 so that it is possible notonly to adjust the antenna to a particular frequency range but also tomore specifically adjust it to a'very specific frequency within thatrange. Each of the contacts .23I to 240 is adjustable along the disc 242between its two adjacent contactors.

Thus, for instance, the contacts 23I to 240 may be mounted upon asemi-circular mounting plate I80 which may be secured as, for instance,

by the bolts -I8I to any suitable support within the housing 25. Themounting plate I80 may be provided with elongated semi-circular slots282, 283 within which the ends of each of the contacts 23I .to 240 maybe slidably positioned. Knurled knobs on the ends of each ofthe'contacts 23I to 240 may be-provided in order to effect securement ofthe contacts Hi to 240 in any desired position with respect to the disc242; such securing means may be loosened so that the contacts 23I to 240may be moved to any other adjustment or arrangement and then once moresecured in position thereat. The two slots 282,

. lar problems may require.

to a stop simultaneously with the insertion of the predetermined amountof impedance in the antenna circuit.

Shaft 245 carrying disc 242 is geared to the motor in such a manner thatrotation of the disc 242 through an angle of the order of 175 willcorrespond to a rotation of shaft I42 to cause impedance I30 to rotatethrough a full range of adjustment.

Similarly, whenever any other operating frequency for the antenna isdesired which requires insertion of a predetermined amount of impedanceto render the antenna resonant at the de-- sired frequency, thedistributor brush 262 will be set on that one ofthe contacts 25I--260'corresponding to the desired frequency or antenna impedance and themotor. 2 will thereupon drive the coil until the predetermined amount ofimpedance has been inserted in then circuit: whereupon the motor circuitwill automatically bedisconnected by the movement of the disc 242 to apositionwhere that one of the contactors 23I-240 which corresponds tothe setting of the brush 262 is moved into the slotted portion 2420ofthe disc 242. I

It will be understood that each of'the contactors 2% to 240 and itsassociateddistributor- 263 are provided so that adjacent contactors.(for instance, 23I and 232) may be moved very close to each other, whichotherwise would .be made diflicult by the diameter of the knurledsecuring members. Mounting plate 460 may be of insulating'material. Or,if desired, for structural purposes, it may be of metal and the.contactors'23i to 240 maybe appropriately insulated from each other andfrom the mounting plate.

By this means, therefore, any. range of frcquencies may be provided forand any adjustments may be made in the apparatus to provide a variedselection of frequency ranges as particu- Also any selection and spacingof various frequency ranges within the range of the antenna structuremay be obtained. v

Suitable means may be provided (especially where manual adjustment is tobe made) to pre-' vent excessive rotation of coil I30 which wouldotherwise permit the conductive follower. I6I to move beyond the end ofcoil I30. Such means may be provided in connection with shaft 245 ordisc 242 to break the circuits to the motoralong either conductor 226 or22I, depending on the direction of rotation of the disc 242 and the coilno. 1

Thus, when the limit of rotation in the in-'- crease" or raise"direction is reached, the circuit I should beopened at conductor 226,while conductor 22I still permits operation in the opposite direction todecrease." Also, when the limit is reached in the opposite conductor,the circuit should be opened at-conductor 22I, while conductorf 226permits an increase operation.

The radio frequency choke coils which are inserted in each of thecircuits serve to prevent contacts 25I to 260 represents a predeterminedimpedance on the antenna circuit and a correradio frequency currentswhichnnay be induced in the motor circuits from; interfering with theoperation thereof. 'when the antenna is insulated entirely from. themotor circuits, choke coils may not be necessary. Another p rpose of.the choke coils is to prevent radio frequency currents from leaking toground from the antenna.

In the event. that it is desired to make the ad justments manuallygforcalibrating purposes to obtain frequency ranges between the predeterpmined frequency range letterings) instead of automatically, the switch265 is moved to engage its manual contact. The onand ofi switch 2| 8 isthen operated to its closed position which immediately illuminates thelamp 2, and lamp 225 is also illuminated, indicating that the apparatushas been set for manual adjustment. Switch 223 is then operatedto-engage either the contact 222 or 221, depending upon whether theamount of inductance to be inserted is to be increased or decreased.

If the switch is moved to engage contact 222, a circuit is completedfrom the negative side of battery through the switch 265 in engagementwith its right-hand or manual contact over the radio frequency chokecoil 224, switch 223 in engagement with its'left-hand contact 222 overthe conductor 22] to the left-hand side of the field winding 2 I 2 ofthe motor 2| l and thence over the common conductor 2, radio frequencychoke coil 216, on-oif switch 2l8, to the positive side of the currentsupply. The motor will thereupon be driven by the current flowingtherethrough over the circuit described above and will vary the amountof impedance of the loading coil I30 in the antenna circuit. When thedesired amount of impedance has been inserted, the switch 223 is movedto its disengaging position andthe on and off switch 2|! isdisconnected.

Should it be desired to decrease the amount of impedance in the circuit,the switch 223 is moved to engage the contact 221, whereupon the circuitdescribed above is closed except that current from the negative side ofbattery passes over the contact 221 of switch 223 and through conductor226 to the right-hand terminal of the field winding, thence through thefield winding, and. over conductor 2 as traced above.

In the latter case, the current in the field winding drives the motor inthe opposite direction from that described in the above circuit fordecreasing the impedance in the antenna.

The apparatus may be so arranged that it may be manually operated in thesense that adjustment to any degree might be obtained without referenceto the automatic adjustment possibilities-obtainable by the use of thedistributor 2H. Thus, for instance, when the switch 265 is thrown fromthe automatic side to the manual side thereof, then operation of theon-oflf key may close the circuit from the negative side of the batterythrough the lamp 225, the radio frequency choke coil-224, the switch223, to, for instance, contactor 222 thereof, the conductor 22l,

' to the left hand. side of the field winding of the pedance willstopwhen the on-ofl key is opened or when the switch position.

The manual operating may be utilized to calibrate and adjust theautomatic system.

, Thus, by manual operation, the impedance may be varied while thetransmitter is in oper- 223 is moved to a neutral V, ation so that testequipment indicates that a most eiiective transmission characteristic isobtained for a specific desired frequency. When this position isobtained, the apparatus is stopped and one *of the contactors 23! to 240is adjusted to a position where its end is in contact with theinsulating section 242a of the disk 242.

Thereafter when it is desired to automatically adjust the antenna totransmit this frequency,

the distributor brush 262 may be set on that one of the contacts 25l-26lcorresponding to the specific contact of the group 23l240 which had beenadjusted as above. The'remaining conductors 23! to 240 may be adjustedin the same manner.

All ofthe conductors 25|a to 260a and the other connections to the diskand motor may, of course, pass through the cable 215 from the antennastructure through the top frame I5 of the vehicle. A suitable connection210 from the antenna to the transmitter may also be made through thecable 2l5.

Likewise, it should be clear that while my invention has been describedas applicable to a remote control or adjustment of a loading coil for asectionalized antenna, it may be utilized in connection with otherimpedance means for the same purpose. Thus, for instance, should avariable capacitance be used instead of the loading coil, the same typeof motor operation and the same type of control system may be used tovary the capacitance in order to vary the frequency range of theantenna.

It will be clear that I have thus provided an arrangement for optionallyautomatically or manually making adjustments in the antenna. Theseadjustments may be conveniently made from any point and do not requiremanual operations at the impedance coil, as has heretofore been foundnecessary. Moreover, both wide and narrow ranges of adjustments areprovided, permittingoperation of the antenna over a wide range offrequencies.

While for purposes of illustration, I have chosen to illustrate myinvention as applied to vertical rods mounted on moving vehicles, itwill be obvious to those skilled in the art that the principles hereinshown may be applied to antennae generally and I am not limited by thespecific example herein given except as set forth in the appendedclaims.

I claim:

1. In an antenna system, a vertical rod a tenna, a loading impedancetherefor, remotely operated means for varying the. impedance of saidantenna, a motor for driving said means, manually operable means forpredetermining the impedance of said loading impedance, and meanscontrolled by said manual means for automatically stopping said motorwhen said impedance has been adjusted to said predetermined amount.

2. In an antenna system, an impedance means therefor, motor drivingmeans for inserting vari-' able amounts of said impedance in saidantenna system to adjust the antenna system for any one of a pluralityof frequencies, a remotely disposed -manual means for predetermining theamount of impedance to be inserted, and means system above describedcontrolled by said manual means for automat- 'ically stopping theoperation of said motorwhen a predetermined amount of said impedance hasbeen inserted in said antenna system.

3. In an antenna system, an impedance means 4 connected in said antennacircuitto adjust the antenna system for any one of a plurality offrequencies, a remotely disposed manual means for predetermining theamount of impedance to be inserted, a source of power for said motor,means controlled by said manual means for automatically stopping theoperation of said motor when a predetermined amount of-impeda'nce hasbeen inserted in said antenna system and means-for preventing radiofrequency currents generated in said motor circuits from interferingwith said antenna system.

" 4. In an antenna system, an impedance loading coil therefor, anelectric motor, means whereby said electric motor controls the amount ofimpedance connected in said antenna circuit to adjust the antenna systemfor any one of a plurality of frequencies, a remotely disposed manualmeans for predetermlning the amount of impedance to be inserted, asource of power for said motor, means controlled by said manual meansfor automatically stopping the operation of said motor when apredetermined amount of impedance has been inserted in said-antennasystem and means for preventing radio frequency currents generated insaid motor circuit from interfering with said antenna system, said lastmentioned means comprising radio. frequency choke coils connected in thecircuits of said motor.

. 5. In an antenna system, a loading coil therefor, a motor forcontrolling the amount of impedance of said loading coil; 9. pair ofdisks insulated from each other and having contactors in contactingengagement with each of said disks, and circuit connections from saiddiskto said motor, and means including said contactors in said circu tconnections for predetermining the angle of rotation of said motor. a

6. In an antenna system, a loading coil therefor, 'a motor forcontrolling the amount oi. impedance of said loading coil; a pair ofdisks insulated from each other and having contactors in contactingengagement with each of said disks, and circuit connections from saiddisk to said motor, and means including said contactors and said circuitconnections for predetermining the angle of rotation of said motor, saidmeans comprising a distributor having segments individual to each ofsaid contactors and connected thereto.

7. In an antenna-system, a loading coil therefor, a motor'forcontrolling the amount of impedance of said loading coil; a pair ofdisks insulated from each other and having contactors in contactingengagement with each of said disks, and circuit connections from saiddisk to said motor, means including said contactors in said circuitconnections for predetermining the angle 'of rotation of said motor,said means comprising a distributor having segments individual to eachof said contactorsand connected thereto, and

means including the distributor brush of said distrlbutor and itssegments for completing circuit connections through said motor throughsaid contactors and segments, said circuit connections being interruptedwhen said segments are rotated by said motor through apredeterminedangle.

8. In antenna system, a sectionalized antenna having a remotelyadjustable loading coil, remotely operated means for rotating said coilfor inserting a variable number of turns in said antenna system, ahousing for said loading coil, anda distributor ring for connecting oneend of said rotatable loading coil to the lower end of saidsectionalized antenna.

9. In combination, a vertical rodantenna, pivotally mounted meansoperativein the event that said antenna engages an obstruction forrocking said antenna toward ahorizontal position, and

means for storing energy during said movement of said antenna to ahorizontal position for'restoring the antenna to its vertical positionand means for damping the retum'movement to a horizontal position- 10.In combination, a vertical rod antenna, pivotally mounted meansoperative inthe event that said antenna engages an obstruction forrocking said. antenna toward a horizontal position, and means forstoring energy during said movement of said. antenna to a horizontalposition for restoring the antenna to its vertical position, and meansfor damping said antenna to control its restoration with a minimum ofvibrations, to its vertical position.

'11. In combination, a vertical rod antenna, pivotally mounted meansoperative in the event that said antenna engages an obstruction forrocking antenna to a horizontal position, and spring means for storingenergy during said movement of said antenna to a horizontal position forrestoring the antenna to its vertical position, and means comprising adashpotior damping the restoring movement of said antenna.

12. An antenna structure comprising a vertical rod antenna, pivotallymounted means operative in the event that said antenna engages anobstruction for rocking said antenna toward a horizontal position, andmeans for storing energy during said movement of said antenna to ahorizontal position for restoring the antenna to its vertical position,and means for controlling the restoring of said antenna, with a minimumof vibrations to its vertical position, said entire 35 antenna structurebeing positioned on an insulating shock absorbing mounting. 13. Incombination, a vertical rod-antenna,

pivotally mounted means operative in the event pivotally mounted meansoperative in the eventthat said antenna engages an obstruction forrocking said antenna towarda horizontal posi tion, and means for storingenergy during said movement of said antenna to a horizontal position forrestoring the antenna to its vertical position, and means for dampingthe restoration of said antenna,'with a minimum of vibrations, to itsvertical position, said means for rocking said antenna. toward ahorizontal position comprising" a vertically arranged pilot whip,arranged to contact an obstruction before said antenna reaches theobstruction and adapted to be rotated toward a horizontal position bysaid ohstruction, and means operable upon rotation of said pilot whiptoward horizontal position to cause said antenna structure to rotatetoward horizontal position. 4

15. In a sectionalized antenna system having a loading inductance coil,a brush contacting the conductor of said coil for connecting said coilto said antenna system, and remotely operated means for rotating saidinductance coil to insert varying amounts of said inductance coil intotuning of said antenna system.

16. In a sectionalized antenna system having a loading inductance coil,a-fbrush contacting the conductor of said coil for connecting said coilto said antenna system, and remotely operated means for rotating saidinductance coil to insert varying amounts of said inductance coil intothe antenna system for varying the frequency tuning of said antennasystem, said remotely op- -erated means comprising a motor rigidlyconcontact with an obstruction. 18. In a sectionalized antenna systemhaving a loading inductance coil, a brush contacting the conductor ofsaid coil for connecting said coil to said antenna system, remotelyoperated means for rotating said inductance coil to insert varyingamounts of said inductance coil into the antenna system for varying thefrequency tuning of said antenna system, and manually operable means forpredetermining the extent of rotation of said inductance coil to inserta predetermined impedance in said antenna system.

19. In a pivoted antenna system, a loading coil, 2. motor for insertingvariable amounts of said loading coil in said antenna system, said motorbeing rigidly connected to said antenna system, and means for rockingsaid motor and said antenna system about its pivot as a unit in theevent said antenna system is-engaged by an obstruction.

20. In an antenna system, a loading coil, a metal housing therefor forstrengthening said structure, and a. rubber bumper encasing said housingto protect said antenna in the event it is struck by an object.

21. In an antenna system, a loading coil, a

metal housing therefor for strengtheningsaid structure, and a rubberbumper encasing said housing to protectsaid antenna in the-event it isstruck by an object, said metal housing having vertical fins, saidrubber bumper comprising longitudinal strips interposed between saidvertical fins. a

22. In an antenna system, a loading coil, a metal housing therefor forstrengthening said structure,- and a removable rubber bumper encasingsaid housing to protect said antenna in-the event it is struck by onobject.

23. In an antenna system, "a loading coil,

'a metal housing therefor for strengthening said structure, and a.rubber bumper of radio frequency insulating material encasing saidhousing: to protect said antenna in the event it is struck by an object.

24. In a sectionalized antenna system, an upper radiator, a lowerradiator, an adjustable loading coil electrically connecting said upperand lower radiators, and a housing for said loading coil and formechanically connecting said upper and lower radiators.

25. In a sectionalized antenna system, an upper the antenna system forvarying the frequency radiator, a lower radiator, an adjustable loadingcoil electrically connecting said upper and lower radiators, a housingfor said loading coil and for mechanically connecting said upper andlower radiators, and means for pivotally mounting said antenna structureon a. vehicle.

26. In a sectionalized antenna system, an upper radiator, a lowerradiator, an adjustable loading coil electrically connecting saidupperand lower radiators, a housing for said loading coil and formechanically connecting said upper and lower radiators, and means forpivotally mounting said antenna structure on a vehicle, said meanscomprising shock absorbing insulating members.

27. In a sectionalized antenna system, an upper radiator, a lowerradiator, an. adjustable loading coil for connecting said upper andlower radiators, a housing for said loading coil and for mechanicallyconnecting said upper and lower radiators, and means for pivotallymounting said antenna structure on a vehicle, said means comprisingsprin g' members for restoring said antenna to a vertical position witha minimum of vibrations in the event it is engaged by an obstruction.

28. In a sectionalized antenna system, an upper.

radiator, a lower radiator, an adjustable loading for mechanicallyconnecting said upper and lowerradiators, said lower radiator comprisinga hollow tubular member and a driving shaft extending through saidhollow tubular member for remote- I 1y adjusting said loading coil.

30. In a sectionalized antenna system, an upper radiator, a lowerradiator, an adjustable loading coil for connecting said upper and lowerradiators, and a housing for said loading coil and for mechanicallyconnecting said upper and lower radiators, and an insulating block forinsulating said loading coil from said lowerradiator.

31. In a sectionalized antenna system, an upper radiator, a lowerradiator an adjustable loading coil'for connecting said upper and lowerradiators, and a housing for said loading coil and for connecting saidupper and lower radiators, said lower A radiator comprising a hollowtubular member, 1

a driving shaft extending through said hollow tubular member forremotely adjusting said loading-coil, and an insulating block forinsulating said upper radiator from said lower radiator and driveconnections from said shaft through said insulationto said loading coil.

32. In a sectionalized antenna system, a radiator comprising a hollowtubular member, an adjustable loading coil connected to one end of saidradiator, a driving shaft extending through said hollow member, andmeans connected to said drive shaft for rotating said loading coil toadjust said loading coil from the other end of said hollow member. I

33. In a sectionalized antenna system,.a radiator comprising a hollowtubular member, an adjustable loading coil connected to one end of saidradiator, a driving shait extending. through asaaaoo said hollow member,and means connected to said drive shaft for rotating said loading coil.to ad- Just said loading coil from the other end of said hollow member,said means comprising a motor,

and means for pivotally mounting said antenna 1 system including saidmotor for permitting said entire structure to be rocked in the event itis engaged by anobstruction.

Y 34. In a sectionalized antenna system, a radiator comprising a hollowtubular member, an adjustable loading coil connected to one end of saidradiator, a driving shaft extending through said hollow member, andmeans connected to said drive shaft for rotating said loading coil toadfor automatically driving said shaft a predetermined amount forpredetermined tuning of said antenna.

36. In a sectionalized antenna system, a radiator comprising a hollowtubular member, an adjustable loading coil, a brush in contact with theconductor of said loading coil and connected to said tubular member, adrive shaft extending through said hollow tubular member for rotatingsaid coil to insert variable amounts thereof in electrical circuit withsaid radiator, -means for automatically driving said shaft apredetermined amount for predetermined tuning of said antenna,-

- and means for moving said brushaxially along.

low member, said antenna and drive shaft being said loading coil as saidloading coilis rotated.

37. In 'a sectionalized antenna system, a radiator comprising ahollowitubular member, an

adjustable loading coil connected to one end of said radiator, a drivingshaft extending through said hollow member, and means connected to saidI drive shaft for rotating said loading coil to adjust said loading coilfrom the other end of said holat the same electric potential.

- EDWARD J. HEFELE.

